drivers/char/random.c:write_pool() cond_resched() needed

Reduce latency for large writes to /dev/[u]random

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Sami Farin <safari-kernel@safari.iki.fi>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/random.c

@@ -1039,6 +1039,7 @@ write_pool(struct entropy_store *r, const char __user *buffer, size_t count)
 		p += bytes;
 
 		add_entropy_words(r, buf, (bytes + 3) / 4);
+		cond_resched();
 	}
 
 	return 0;